Hello Mark, thank you for providing the video! Can you help me understand the last calculation step of the impact force? How do you derive the formula of F = Weight * dv / g? Thanks!
Hi! You're wecome! Since we're using Lbf Force for weight of object instead of Newtons Force, we can equate the Momentum (mass x change-in-velocity) as: Lb Weight x Final Velocity in Ft/Sec (if dropped from rest), in the US System of Measure. Followed by dividing that product into gravitational-acceleration or 32.2 Ft/Sec^2. We will have to do the calculation that way IF USING the US System of Measure. If we're using the Metric System, then it is Kg-m/s^2 or (mass kg x change-in-acceleration m/s^2) WITHOUT needing to divide into graviational acceleration (9.81 m/s^2). This is because Absolute Weight in the US System of Measure is Slugs. 1 Slug = 32.2 Lbf Weight. This unit is what correlates Lbm x Gravity with Lbf Weight. It seems like Force-Weight = m x g is only evident in the Metric System. However, what differentiates Lbm from Lbf is the Absolute Weight or 32.2 LbF Weight per Slug. The easy way using the US System of Measure is: [(Lb Weight x Final Velocity Ft/Sec) / (32.2)] ===> Impact Force in the opposite direction or the same value, but a negative (-) value. This is the Normal Force in the opposite direction immediately after impact ===> Newton's Second & Third Laws of Motion.
Yes I would be interseted. I cringe to understand the real purpose of your video. How many Lives were lost by gready govermental permissions to use cheap lead in gas , what will we find out about the fuel we use now in the future . Why not use your knowladge to help figure out a way to bring down the cost of something that is good for you the earth and everyone else. Is this what you were educated for . To fight change for good. Left up to you I wonder how many more people would die just so you can save some money.
Hi! You may want to view this video: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-qIH7iaX4wiY.html Design plans and narrated-lecture regarding a technology congruent with your inquiry(s). The first Alternative-Power-Concept (in green). 'Non-Combustion Compressed Hydrogen Gas Piston Engine'. Cost-effective, environmentally-friendly, and high energy-density. Hydride-Electroysis of Water split into Hydrogen & Oxygen gases: 66.7 times less expensive compared to DC Current Water-Electrolysis Feasible Liquid-Hydrogen filling-stations: cost-effective Gaseous-Hydrogen liquefaction to Liquid-Hydrogen. Non-Combustion Liquid-Hydrogen Gas-Expansion-Ratio = 1:848 Emissions: 100% Water Vapor. Thanks for your comment!
Among the fastest methods, yes! This video was more of a "proof-analysis" to fall-back-on, if faster methods are not understood. Thanks for your comment!
Well, I put my comments under the video I refer to. . My comments ALSO pply to this video and I am very disappointed. I seriously recommend that you remove it because it is wrong. . I have now looked at THIS Part 1 video. . You have awkward ways of explaining things and use unconventional terms such as "Bernoulli pressure". I won't explain it all, but here are representative samples. . You say that a fraction such as A/B is "A divided into B". Whereas, this is correctly stated: "A is divided BY B. or B is divided INTO A." . I am sorry, but I must be candid with you. This demonstrates that you fail to under simple physics. After 20 minutes you show that you do not understand that a sustained climb of 800 feet per minute is a CONSTANT vertical speed, NOT acceleration. It is a vertical SPEED of a constant 13.333 feet per second through out the entire climb. There is NO change in vertical speed. Therefore, that calculation is wrong and does not belong there at all. It DOES NOT add to the Acceleration of gravity. . You show an incorrect equation at t=8:15 in Part 2. "13.5 psi x 6894.76 = 930,79 Pa" Which should be: "13.5 psi x 6894.76 = 93,079 Pa" . In addition, you use the wrong equation for distance even when there IS acceleration! For the relationship between the Distance traveled "D" at a CONSTANT Acceleration 'A', over time 't', is: D = 1/2 a t^2. Distance equals ONE HALF A t-squared. . Finally, it appears that you somehow think that the vertical displacement due to Rho*g*h is significant when you mention the wing's 'projected' height. That is fully irrelevant and never considered in real aerodynamics. I simply couldn't struggle more of this video. . I had wondered if English is not your first language because your phrasing is very awkward, but I do not detect an accent. . I am sorry, but you have failed to correctly apply physics and have a very magical interpretation of what a constant rate climb is. This is not the quality of accuracy and knowledge I have experienced in my professional career with other engineers and that I expect from a real engineer . If any of this, or Part 1 is what you learned to get your Associates at Western Michigan University, then you have been done a great disservice and you provide no service to others with these faulty videos. . I seriously recommend that you remove it all. Sorry.
Steve, your perceptions are totally flawed. You are a technician not an engineer. "Associate" degrees are not offerered at universities, only four-year Bachelor's degrees are. lol Until you complete a four-year Bachelor of Science in an engineering discipline at an accredited university (like I have), you cannot call yourself an engineer. Your US Navy career as an electronics technician means nothing. Your civilian career as an electronics technician means nothing. Your fixed-perceptions of "science" since high school means nothing. Your son earning a four-year engineering degree has nothing to do with you. I think you're you're a bit alienated and lonely, and have a bone to pick with other YT users. Complete your four-year Bachelor of Science degree in a STEM discipline, earning a 3.50 GPA or higher. Do that first. Then you may realize there are multivariable methods of deriving solutions. You failed to even understand that vertical-climb-acceleration is NOT instantaneous! VSIs' will never instantaneously "jump" to "800 FPM" climb! Therefore, vertical-climb is an average-rate-of-acceleration, or distance divided into time squared. Ultimately, the idea is to calculate total absolute pressure at the lower wing surface. Which is a summation of: (average lift-force / 2D-wing-area) + (force-wieght / 2D-wing-area) + (atmospheric pressure). The Average-Climb-Acceleration must be derived first, as a product-function with airplane mass, to yield average Lift-Force. You need to know that Projected-Height-of-Airfoil increases with increased-AOA. The bifurcated boundary-layer-airflows (upper & lower) incur increased height differential at increased AOA. Which induces inversion of kinetic and potential energies across upper & lower bifurcated airflows: Upper surface airflow will increase in kinetic energy (velocity), and lower surface airflow will increase in potential energy (pressure). A function of h2/h1-Differential across the 'Bernoulli Equation'. This is why Symmetrical Airfoils disprove "Transit Theory". It is NOT "distance differential" across upper-and-lower-wing-surface-lengths. It is Projected Height Differential (h2/h1) with increased AOA. This inverts kinetic & potential energies at upper-and-lower-boundary-layer-airflows, respectively. Lastly, most of your comments are littered with numerous GRAMMATICAL ERRORS and FALSE STATEMENTS. But, I chose to look past that, and instead have a civil conversation with you. No need to get mad at me due to your insecurities. But, if you want to call yourself an engineer, first complete your Four-Year Bachelor of Science degree in an engineering or STEM discipline at an accredited university, earning a 3.50 GPA or higher. A 30-year-long career as a technician, does not make you an engineer. If you actually read my previous comment at the 'Aerodynamic Lift' video, you would know that I retired from a previous aviation maintenance career after earning a Two-Year Assocate of Science degree from a Community College + FAA A&P License + seven (7) years of experience in the aviation maintenance industry. FOLLOWED BY 'starting-all-over-again" and completing a Four-Year Bachelor of Science degree in Aeronautical Engineering at Western Michigan University, earning a 3.68 GPA. Subsequently working for several Start-Ups, and also teaching STEM coursework at private charter colleges for the last five (5) years. I don't why you are "disappointed" with me Steve. If anything, you should be disappointed with yourself for coming to my channel and posting comments about "engineering", when you yourself are not a degreed engineer.
@@markscythian7179 I see you can't address any of the points correctly. Sorry. Your assumptions are far off. Your research has also failed you, here . With other studies, I have a full BS University of Illinois '71 - High in my class. Second highest offer from a leading development company. . I also learned from and discussed some of these very things with leading aerodynamics authors / professors. . You ignore your most obvious errors and just go ad hominem. . In the older video you state two of the most common fallacies. The second and third items on that July 16 2016 paper. . - Higher speed flow has lower pressure than ambient - we easily measure the jet from a blower with a standard static pressure probe as having static pressure the SAME as ambient pressure of the still, near-by air, NOT lower as you state. - Lower speed flow, in relation to ambient will be at a higher pressure than ambient - Yet it is well known that stagnation pressure of a jet toward a surface is at the SAME speed as that stationary, ambient, yet has a higher pressure. Not to mention that is is hard to go slower than still air, thus a poor claim. You also can't clearly define what the ambient air is. . . . In addition, in my Fig 7., I show measured data showing that the air below a wing has higher pressure than ambient, but is accelerated to a higher speed that the air above the wing when referenced to the stationary air's inertial frame of reference. Also showing that the upper air has a greater acceleration. Therefore clearly showing that the 'faster' air having lower pressure, is a fallacy. . Yes, there is accelerations at the start and end of a climb, but only for a short time. while the bulk of a smooth limb is with a relatively steady VSI. Thus, making your calculation using 800 f/s *completely* invalid. AND ignoring that it is the incorrect equation to boot even if it was a constant Acceleration of 800 f/m^2. . . Remember that the 800 f/s is YOUR definition - and that equation is incorrect as I carefully explained . There is no way to defend that and simply denying that is not refuting with any justification. . Your made up term of Bernoulli Pressure". . You refuse to admit your misconceptions and errors expressed in those videos. Too bad. I took the time to watch and carefully detail the errors, but you won't even try to provide justification because you can't. Have a good life.
@@Observ45er Steve, most of your assumptions about me are wrong. English might be your second language. You make so many grammatical, spelling, and sentence-structure errors. Not an aspect of a university graduate. You have so much to offer, graduating at nearly the top of your class (University of Illinois), and decades of experience. So, why don't you have much content at your YT Channel? All I see are two (2) videos, and 47 Subscribers at your YT Channel. Not an aspect of an "expert". Are you scared of publishing your work on YT? Why are you hiding out at your own little site with insignificant traffic? You're unaware of my intention(s) regarding this two-part aerodynamics video series, designed for audiences with very basic intro-level aerodynamics experience. Nothing too complex. STEM graduates are a very tiny market. Can't reach as many people compared to the general population. Now you know the marketing side of why people do what they do. Crazy people are 'concrete thinkers', categorizing everything into "black-and-white". Reality is not ideal. In fact, reality is highly abstract. Which is why I set my videos up the way I do. If you are as qualified as you claim, then surely, you would have published more than two (2) videos and have more than 47 Subscribers at your YT Channel! lol You want to disprove me, go ahead. But so do by making videos on your own YT Channel, rather than flooding my channel with your comments. Don't be lazy. You'll have to start publishing far more content at your YT Channel for the world take you seriously. We'll just leave it at that. Have a good life Steve! Smiles. :)
@@markscythian7179 Hi Mark, I understand your desire to help others, your good intentions. That is a good goal. . My aviation interest started in grade school since my dad learned to fly in biplanes and was an engineer with intense interest in fully understanding many things. And, yes, long ago I saw “equal transit’ in ground school, but wasn’t interested in anything but passing the test because the pilot license was a side interest from my chosen profession of engineering. . I built many model airplanes and did considerable radio control. . In the Navy, after high school, I was asked by Command to teach others in technician school. . After my BS at U of IL, in my professional capacity I learned from others & mentored less experienced engineers . I gave seminars as part of my profession as a development engineer. Along the way, I was as asked by two colleges to teach, as well as two elementary schools and scouts to do to STEM demos. . Volunteering at one of the 30+ national Challenger Learning Centers, I ran SETM demos for students and adults and was asked to manage the full cockpit flight simulator, donated by a local aircraft controls company, shown in my Quora Blog. I had 5th and 6th grade students landing the Space Shuttle at Kennedy Space Center in it. . Because I put aside flying decades ago, it was that simulator that motivated me to brush up in many aviation related areas, knowing I could be asked all kinds of questions by attendees. . Seeing all the lift misconceptions spread on the internet, by so many people with those very same good intentions to ‘explain’ physics to others; I read the writings of some well-known teachers and authors such as John D. Anderson, Anderson & Eberhardt, Doug McClean, Charles Eastlake, Holger Babinsky, Mark Drela and Krzysztof Fidkowski. . I also contacted some of them to insure I had complete understanding of various points. And, yes, my son, Embry-Riddle AE Grad who works in aircraft engineering, was a good resource to discus and clarify some things that helped me better explain things going forward. . I’ve also engaged in discussions under some of the many RU-vid videos to learn how others viewed the misconceptions, so I could better explain things going forward. Good teaching requires knowing your audience. . My observations, NOT assumptions, of your videos comes from that background and that you clearly made errors: … In simply writing numbers thus: “930,79 Pa”. NOT good engineering. … Treating an 800 ft/min constant Climb as an 800 ft/sec^2 acceleration. … Then, using a faulty equation to calculate the nonexistent acceleration that does not add to gravity in the physical world. ... A significant one I mentioned earlier where you say: "because of the curve, the airflow will want to speed up and accelerate". What principle in physics shows us that a flow has a desire to speed up due to a curved surface up ahead? . Those errors are IN YOUR videos and I see you have nothing to say about them, but vague, non physics comments about crazy people, the 'wants' of air and numbers of RU-vid videos. Can you either agree you made errors, or refute any with physics principles that support your claim? . . . . . . The worst thing is that you won’t own up to your errors and learn. That is not what I, my father, nor the many good engineers I’ve worked with for decades, would do. Full understanding of our craft and the best possible designs were always the combined goal. . I’m sorry to be candid like this, but if you are actually working in aviation as an engineer, I recommend that you ask some authoritative aerodynamicists to review your videos and see what they say. My solid knowledge and experience tells me they will undoubtedly agree with me. . . . . Actively working for decades with the national Challenger Learning Centers, two elementary schools & colleges, scouts and beginning engineers is hardly a sign of laziness. . . In closing, IF your only metric is the number of RU-vid videos that indicates true expert knowledge, then you’ll worship this guy with new videos every few days and the way he describes Aerodynamic Lift, here. .Copy and paste the link and it should skip the beginning chatter at 3:53: . Sometimes RU-vid deletes URLs so fix the DOTs. . www. DOT youtube. DOT com/watch?v=VhReoAJZzpE&t=233s - - Good luck going forward.
l'hopital to the rescue you'll just differentiate both the numerator and denominator and be left with (3x^2)/2x and then plug in -2 as x to get 12/-4 --> = -3
Thanks for the correction! Should be a (0 / 0) 'No Solution' condition, rather than a (16 / 0) 'No Soution' condition. I'll re-do this video for total accuracy sake. Thanks again!
Depends which Americans. We are a Free-Market here in the US. No level of (attempted) centralization of anything will ever occur in the US. Unless that is what the People want. Top-tier American families, students, and communities invest maximum time and funding toward their kids and/or school districts. These segments of America acquire world-class education at the High School level. Relating the US & Metric systems across all applications of measure is key. The point of this video is that the Metric System is a completion of the US-English System of measure to absolute certainty. The US & Metric systems of measure are to be learned simultaneously, and should never be separated. If you learned (both) the US & Metric systems across all applications of measure, that is outstanding! However, on an American systemic level, we have not (yet) implemented Road Speed Limits and Volume Quantities of Gasoline in Km/Hr & Liter units. This encourages American society to disregard the Metric System. Hopefully we can agree that this is true. Most Americans still believe that the Metric System is a "foreign" system of measure. When in fact, it is the US-English system of measure corrected to universal absolute certainty. Thanks for your comment!
@@lolololo4496 I've been so STEM-focused, didn't realize your JOKE! LOL. Yeah, 9mm rounds discharged in American schools aren't uncommon these days! You know the history about the 9mm pistol, and how it made its way into America around the late 1930's? Well, at the time (1930's), America laughed at the idea of 9mm caliber/diameter replacing the manly .45 ACP. 9mm = .354 cal. Ha ha ha... But, in fact the drop, impact-pressure and ballistic power of the 9mm outperforms the .45 ACP, except for impact-force. 9mm probably more lethal depending on shot-pattern and body weight, can carry more rounds too. I "think" the 9mm design program originated from Mauser 8mm (overseas) and morphed into the 9mm here in the US around the 1930's or 1940's.
Matter & Energy are one and same, existing in different mediums. Atoms are 99.9999% empty space. Matter is the concentration of atomic energy or 'Quantum Entanglement'. For example: If matter such as a "spacecraft" is able to reach the Speed-of-Light (3.0 x 10^8 m/s), it would no longer be matter, but convert into light (energy). Matter and Energy are the same, but across different mediums. E = mc^2. The LASER beam, while pure energy, has matter potential across its coherent waves as well. The equivalent matter within the LASER beam is then equal to: m = E / c^2. In this case, one-half of the LASER's Watts Power would transfer as Thermal Power in Watts (Heat), at the LASER's point-of-contact with target. The LASER's matter-component in the form of Plasma (4th State of Matter), would translate to: 1000 W / (3.0 x 10^8 m/s)^2 or: 1.1 x 10^-14 kg, moving at the Speed-of-Light. Or around 500 Watts of heat projected across the laser to its target, having considerable range.
Let mid-point of AC be M and theta = angle MBC. BC = 1/cos(theta), AC = 1/sin(theta). Area of ABC = 1 (2 x sin(theta) x cos(theta)) = 1/ sin(2xtheta). In this case, theta = 45. So, area of ABC = 1 / sin(2 x 45) = 1.
Yes it will. Provided the RPM differential across all pullies is accounted for. The Length (L) is the distances from the pulleys planes-of-rotation (center of their bearings) to the outer tip of pulleys. Each pulley's mass (m) in kg TIMES each pulley's radius length (L) in meters TIMES the parenthesis quantity of each pulley's (Revolutions Per Second x 6.28)^Squared, then DIVIDED into 4.45 to calculate each pulley's Centrifugal Force in Lbf.
Wave Particle duality is a result of human interference. IMO this would not exist without human manipulation to make light appear as both a wave and particle.
Hi europaeuropa3673. Very true. Human Consciousness is the primary "infinite probabilistic information" stream setting forth energetic quantum entanglement into what is perceived as matter. The original video I had produced on this topic intimately covered this principle, consistent with the 'Double-Slit-Experiment'. However, it ran too long, spanning over 1 hour, and 37 minutes. lol Therefore, I uploaded a much shorter and abbreviated version of the original video. Thank you so much for your comment!
Mark, I am friends with Pawelz. I need to talk to u so you can pluck some ideas out of my mind. We could the 3 of us make some cash together and do good for mankind. HHO Turbine idea, LED with 3 colors Black, White, and prism
A couple of quibbles: This seems to assume that 100% of the fuel energy is converted to heat, but isn't ~5% turned to light? Also, combustion must be something less than 100% efficient; paraffin wax candles are strong soot producers.
Thanks SibuJacob! The presented Propeller Thrust Equation (Static & Dynamic) is derived from the 'Simplified Momentum Theory'. Then scaled for practical applications by introducing greater Degrees-of-Freedom (DOF).
@@markscythian7179 Quite a view perspectives on that Topic. I guess, Constant velocity or perhaps just no temporary loss of pressure on the way out avoids unnecessary heatlosses.? I mean building up pressure at constant volume ends in a certain amount of heat so or so. I m on optimizing centrifugal fan for an airbad hover thing at the moment 😂 Indeed, different ambient conditions, pressure on the outlet dominated by build up weight, not atmospheric. I m wondering if smaller cross-section of blower outlet can build up more pressure 😮 And if in my case stator plates can improve pressure power. May have some kinetic to potential energy conversion effect. Interesting view when looking on multi stage compressors! Any hint saves me a 3d print😊
I'm a little confused by the syntax in your equation. Why have you separated everything after the fraction (diameter over pitch) from everything afterwards? Is everything in the second set of square brackets meant to be subtravted by v0? If not, why not combine the two constants and write RPM^2?
Hi William. These equations are hybridized iterations of the 'Simplified Momentum Theory'. Thus, calculating Propeller Thrust (Static & Net) with accuracy. As with any mathematical expression, Order-of-Operation (P.E.M.D.A.S.) is required. Not just for accurate computation, but also to determine the order of mathematical computation. P.E.M.D.A.S.: 1.) Parenthesis. 2.) Exponents. 3.) Multiplication. 4.) Division. 5.) Addition. 6.) Subtraction.
Similar, but not the same. Half the mass of the wheel, its Radius and RPM are used to compute Centrifugal Force of a wheel. The wheel's outward tensile force at a given RPM will equal its Tensile Centrifugal Force.
Mark how would I figure out the safety limit of a aluminum flywheel with magnets cut into the faces of the round disk?? The electric motor will be spinning at 3600 R.P.M. max. What would the diameter need to be for safety reasons ?? Nice and interesting video Mark too. Have yourself a Merry Christmas and a Happy New Year too. vf
@@victoryfirst2878 Drilling Soft Iron or Neodymium magnets is difficult and tedious. This may distort the Magnetic Lines-of-Flux into infinite feedback loops. Drilling magnets is not recommended. An acceptable method to fasten magnet(s) onto rotor could include top-down slide-insert and Sheer-Fit. A non-magnetic Hard Chrome top-plate could then be installed plush for magnet containment and held in place with a Cam-Lock. Simple yet effective. If sufficient rotor thickness is allowed, centrifugal force should not overcome sufficient thickness. Rotor mass, diameter, and RPM are logarithmically proportional to centrifugal force. IF you are building a 'Magneto-Heating-Element' to harness high voltage impulse DC, Armature Step-Up Coils/Inductors or Step-Up Transformer(s) may require Bonding-Straps to support electrical and thermal grounding. Electrical and Inductive grounding along with Heat Sink(s). Armature Coils are (practically) R-L-C DC Circuits. Initially, Rotor/Stator relationship is Sinusoidal and rectifies itself at the Armature Coils. Ceramic heating elements and ambient air reflow have solved many problems with respect to Heating Efficiency. A heating system commonly used in aerospace/defense applications, now slowly moving onto the civilian market.
Seems like there should be some dependance on air density as thrust should decrese with decreasing altitude and density. Unclear if the constant accounts for this (maybe assuming sea level?)
The formula demonstrated in this video describes experimental propeller thrust yield(s). An accurate (static & dynamic) propeller thrust formulation derived from the 'Simplified Momentum Theory'.
In Point 6) at 9:00 you mentioned, "Propeller Efficiency (80% Industry Standard)." What do you define efficiency? Is it efficiency of the connected Brake Horse Power (BHP) in the case of propeller, or Shaft Horse Power (SHP) in the case of rotor?
Hello Mark! I've sent you an email a few weeks ago regarding one of your older videos but I didn't get any response. Could you please check your inbox and send a reply if you wish? It would be greatly appreciated.
Your example had two blades each of 11.5 lb, but you only used the weight of one prop blade in your example. Had you used the weight of both blades, your force would have been double.
True. Thanks for the correction! Correction: TOTAL WEIGHT from Plane-of-Rotation or (11.5 Lb x 2), then divided into 2.2 to compute mass Kg, this value then multiplied times meters length of radius from Plane-of-Rotation. This product then multiplied times angular velocity or [(RPM / 60) x (2 x Pi)]^2, to compute Cf in Newtons force. Newtons force then divided into 4.45 Nf/Lbf to compute Lbf Centrifugal Force (Cf).
Sorry, Mark. This is perhaps the most wide-spread misconception related to aerodynamics. You have some understanding of Newton, but you failed to apply it here, Mark. . I'm surprised no one has pointed this out in 6 years. I just ran across this looking for another wrong video I saw a week ago. .. . Your statement that: "Higher speed air flow in relationship to ambient air, it will exist at below atmospheric pressure." IS ABSOLUTELY FALSE ! .. This is easily measured on a daily basis by engineers and students. .. Look up Bernoulli's Principle on Wikipedia. The speed increase OCCURS SYMULTANIOUSLY WITH a decrease in pressure or visa versa. An increase in speed is Acceleration. The air itself is CHANGING speed.!. The two pressures are at two DIFFERENT locations before and after the Acceleration -WITHIN the SAME flow. A change in speed/velocity is Acceleration. . The two pressures are ALONG a flow. That is called a Pressure Gradient - - - 'Gradient' because it is a fundamental fluid property that the pressure varies gradually between the two. .. Bernoulli's Principle is about Acceleration, NOT speed. When you see an _acceleration_ of some fluid, you will see an accompanying pressure change - NOT simply a difference between any two locations.!.. .. In the mid 1700s, Euler, following up on Bernoulli's work ,determined that Newton explains it because a Pressure Gradient causes fluid Acceleration. In J.D Anderson's Book. .. Where Bernoulli comes into play is INSIDE the blower. The air out of any 'blower' is because there is a higher pressure inside it than the outside, atmospheric pressure. That's where your pressure drop is [inside to outside] and the speed increase [inside to outside]. The high pressure in your lungs pushes more on the intervening air than atmospheric and that provides a net force Accelerating the air into the atmosphere, where is assumes atmospheric pressure. ALSO, if that air stream was lower than atmospheric, it would get squeezed smaller and smaller as long as it was moving and we easily see that is is expanding. <--problem. .. The longer path fallacy is easily disproved by a *flat* wing or an verted asymmetric wing. <--problem. .. The entire upward lift force is due to the Top-Bottom (static) pressure ion the wing.!. Increasing the AoA simply increases the difference. .... The physics is that a Pressure Gradient causes fluid Acceleration - - this is just like a force is the cause of acceleration (Newton. Bernoulli is Newton for fluids. .. .. .. The higher speed above is CAUSED BY the Pressure Gradient between ahead of the wing (ambient) to above it (below ambient). . The curve *IN THE FLOW* is indeed the main factor in the cause of pressure decrease, but not because of the longer path. Another fact: The curve in the flow is also the main factor in the cause of pressure increase there. ... The reason the upper air-flow curves; is because the atmospheric pressure provides the centripetal force. REALLY HARD.!.!. Atmospheric pressure downward on a 172 wing amounts to a force of around 350,000 lbs.!. DO the math. . The pressure pushing DOWN on the wing's upper surface does not go away when it moves. These pressure changes are really small. The upper pressure pushing DOWN on a Cessna 172 wing decreases by about 0.08 psi.!. <--FACT. The Top-Bottom difference is 0.1 psi on average.!. Over 25,000 (planform) sq-inches area is the 2,500 lbs craft loaded weight. Look up the wing loading and convert to PSI. .. .. Your first drawing is *greater than* zero geometric AoA.!. That wing even AT zero *geometric* AoA still generates lift for the same treason _ALL_ wings do. .. The SAME occurs when a wing is generating lift, REGARDLESS of the _geometric_ AoA. There is also an _effective_ AoA, relative to the zero lift orientation. .. .. There are not two lift vectors. You are not describing any physics for your "Newtonian" lift. "Elaborating" is not a physics explanation. <--problems. Upper air *Decelerates* near the trailing edge because it is traveling toward an INCREASING pressure - this is called an Adverse Pressure Gradient. . The reason lift has a forward component is because the largest pressure difference is about 25% back from the L.E. where the upper surface is still angles forward. AND that decrease in pressure occurs where the sharpest air-flow curve is above the wing and where the lowest pressure occurs. .... Full explanations for Bernoulli and lift are here: *rxesywwbdscllwpn.quora.com/* - - Cheers
@@markscythian7179 Mark, While advanced topics can be piled on to add even more confusion, your video contributes to the 'marketing' of the incorrect information you refer to. In other words, it perpetuates it - adding to all the other noise. . If, as you seem to indicate, you have since learned better, why leave it up? .. The thing with Tyson is that he has a large, existing audience and he's spewing more of it. He hasn't responded to my query, yet and I have other things in process. . Even NASA provides elementary school material with bad information and the usual misinterpreted demos. . I'm a very experienced engineer, mentor and teacher who gets paid for a track record of understanding what I'm designing and explaining. . Taking over management of a full cockpit B737 flight some some years ago, I recalled the equal transit story from ground school many years ago and decided to brush up on many things 'aviation', since that was obviously bogus, though I chose to pursue electrical engineering as a career. My son with an AE from Embry-Riddle helped with this and I've already read and talked with several well-known names in aerodynamics. .. Being a pilot is no credential for physics, since nonsense has been taught to them - nor is an understanding of the correct physics required for the left seat. .. Do you actually think that adding yet another video will actually help? .. Just like here, I occasionally run across another video or paper and try to engage the author, but few are serious enough to care - as long as they have their 15 minutes of YT fame. . . You're one of the few who cared enough to respond. .. When carefully laid out, explaining the correct physics concepts of pressure changes around a wing is not more difficult than what you have in about the first half here, except two of those things you mention must be understood (acceleration and inertia). It's easily high school. Could you see that in the blog I linked above? it needs cleanup, though, but shows the essence. .. I still have some energy for this, but with all that bad information out there, there may be a time to make the decision to give it up, since it won't affect any lives to any degree. Those working with it can either understand it, or give a popular answer that it's all in the B-S-math, Kutta, etc. without explaining any physics. . Possibly to be continued. . .
Hi Observ45er! A lot of new content has been added. I think you have been watching too! lol Thought of you when I uploaded: 'Applied Aerodynamics Part 1 & Part 2' videos to my channel. 'Why Airplanes Fly' disproves "Transit Theory".
@@markscythian7179 Hi, Mark. If you are a very good A&P, you should be proud of that and I recommend you help others learn in that area, but learn more physics to better understand lift. . I don’t know if you’ve added content to this video since I saw it a year ago, but now, you say there is ‘nothing magical’ and it is ‘applied physics’. . Unfortunately, when you say that above a wing "because of the curve, the air flow will want to speed up and accelerate" (time 2:50) that's pretty magical. There is no physics principle that says fluids will spontaneously accelerate on their own, because of some internal desire, nor that they realize they have a longer path to travel. That that is neither Physics, nor applying it. . Newton's First law clearly states that without a force, an object will not accelerate on its own. Fluids have mass and, therefore, they follow Newton’s laws. Newton’s First law makes it clear that force is the cause of acceleration and a pressure gradient is what causes the force to accelerate fluids. . Fluid does not spontaneously speed up because of some desire it has. . Air has mass and if you study Newton’s 1st law of motion, you find that a force is the cause of acceleration. . I explained in my comment a year ago, that Euler determine this following up on Bernoulli's work in the mid 1700s. Euler realized that it is a pressure gradient, which produces a net force on fluid, therefore accelerating it away from the higher pressure region towards nearby lower pressure regions. This is where Newton is also valid for fluids. . ^^^^^ *That* is Physics and that is how it is applied. . In addition to what I pointed out a year ago, you make too many errors to outline them all here. You misuse terms; there is no such thing as a Bernoulli force; Bernoulli does not explain the formation of a boundary layer; you mentioned a vacuum differential with no explanation of what you mean, the pressure along the top surface of the wing is pushing downward and the angle of attack is not the 'shape' of an object to oncoming airflow. AoA is the ORIENTATION of the airfoil relative to its direction of motion. You are also hunting for what you mean by a definition of the ambient air around the wing and seem to make it whatever you wish rather than what it is: the bulk air that the wing is flying through. . Lastly, your diagram of the airfoil with the lift, drag and weight vectors is incorrect. You show it as the wing is descending rather than flying in horizontal flight. By definition, the lift component of the total force on a wing, is directly opposite the weight (180 degrees), not at an angle as you show. The weight is towards earth, straight down, and the lift is directly away from that straight up. The Drag vector is also much smaller, therefore, shorter than the lift vector. . I highly recommend reading my lift Blog. Because RU-vid appears to be deleting comments with links in them, I’ll try this. You'll have to reassemble this link to my Blog explaining lift, by putting the dots back in. It explains the correct physics of Bernoulli's Principle and lift, step-by-step, as well as why common misconceptions are false. rxesywwbdscllwpn DOT Quora DOT com/ Regards. I'll check back later to see if this comment gets deleted. . .
@@Observ45er Emphasis on the Height Differential (h2, and h1) was the main takeaway of 'Applied Aerodynamics Parts 1 & 2'. Not "curvature", (Transit Theory is WRONG): As the AOA increases so too does the PROJECTED HEIGHT. As Projected Height increases, so too does Kinetic Energy or Velocity on the upper wing surface or airfoil. (rho)(g)(h) correlates with mgh or Potential Energy = Pressure. (0.5)(rho)(v-squared) correlates with 1/2pv^2 or Kinetic Energy = Velocity. Both sides of the Bernoulli Equation w/ respect to P1 & P2. The zero AOA's Projected Height is the Airfoil Thickness or h1. The max AOA's Projected Height is h2. Before I became an Engineer, I was an A&P. Most A&Ps' are stuck in PV conversely linear relationships, absent of the Bernoulli HEIGHT DIFFERENTIAL! A&Ps' who continue on with their BSc. and earn their Physics or M.E. degrees gain rigorous experience with Bernoulli differentiation and integration. Some do (5%), most don't (95%).
Hi. Yes. High Torque, and much lower RPM. GE90-115B Fan is 128 inches in diameter (3.3 meters in diameter). Maximum Fan RPM is 2,355 RPM, but its Torque is 179,372 Ft-Lb @ 2,355 RPM (243,946 N-m @ 2,355 RPM). A large diameter Fan cannot rotate as fast as a smaller diameter Fan, because the blade-tip-speed will reach the Speed-of-Sound at much lower RPM. Fan and propeller performance limitation(s) occur at blade-tip Speed-of-Sound. A ducted fan or propeller can rotate slightly faster than an unducted fan or propeller. Large Fan diameter equates to greater circumference, thus reaching blade-tip Speed-of-Sound at much lower RPM compared to smaller diameter Fan.
Wave cancelling and why laser pointers look like they do - A question I'm assuming the light of a laser pointer is one wavelength Is the reason laser pointers scintillate because of wave cancellation? They appear to have dark spots that come and go.
Awesome video! As centrifugal forces increase, does thrust and drag bending force decrease? I'm curious if blade deformation is less pronounced at higher rpms....
Thanks! Thrust-induced bending force is a function of mechanical power (BHP) delivered to a propeller. Bending force induced by thrust is superseded by centrifugal force. Example: Semi-rigid propeller fan blades on a turbofan engine will have 1/10 the thrust bending force compared to the centrifugal force at the blades when at maximum power. The same is true with open propellers on piston and turbine-driven aircraft propellers. Assuming the propeller is properly designed with material and dimensions having the correct Young's Modulus (E), the centrifugal force may be at least ten-times higher than the thrust bending force. The thrust bending force on semi-rigid propellers also reinforces or enhances longitudinal strength, thus increasing thrust or lift 'control authority'. This is especially true regarding helicopter rotors. Thanks for your comment!
For my preliminary design calculations I had a gap before I could justify the jump to in-depth empirical work. You solved my month-long issue in 15 minutes. Thank you.
Hi! Within the related disciplines of Physics and Mechanical Engineering, "N" typically refers to 'rotor speed' measured in radians/sec. However, with respect to an entire Compressor-Turbine-Spool, "N" is construed as Categorical identification for single or multiple plane(s)-of-rotation, rotors, drive-lines, spools, discs, shafts, and controlled mass-rotation. "N" in this particular case serves as Categorical identification rather than a Numerical constant, variable or coefficient. Thank you for your comment and question!
